Overview of Powerline Carrier Technology
 

A Powerline Carrier System is a method of sending information over 120 volt, 60 Hz (or 220 volt, 50 Hz in Europe) electrical power distribution system within a building or facility.

In the past, Powerline Carrier Systems have been limited in their applications because they have suffered from unreliable signal transmission, due to the large amounts of electrical "noise" and "transients" found on powerlines. This electrical noise is caused, for the most part, by the normal use of appliances and machinery in homes, offices and factories. Past attempts to solve these problems have resulted in complexity and expenses that have priced powerline carrier systems beyond the range of many applications.

Cepco's Powerline Carrier System offers a unique solution to these problems using technologies that are covered by United States, British and Canadian patents, with other patents pending. This technology allows the Cepco Powerline Carrier System to be every bit as reliable as direct wire systems, with the added advantages of being more flexible and far less costly.

The key to the success of the technology is in the fact that it allows for the economical inclusion of such features as:

• High level Digital Pulse Modulation at the zero crossings for reliable transmission.

• Automatic transmitter synchronization that allows multiple transmitters to operate simultaneously without interfering with each other.

• Automatic noise detection and evasion.

• Multiple code word commands that virtually eliminate the possibility of false commands.

A transmitter unit is used at one location to impose a coded signal on the AC power wiring and a receiver unit (receiver module, monitor panel, or display panel) is used to receive, decode, provide control and/or display this signal at other locations. In this system no new wiring is required for signal transmission.

The Cepco Powerline Carrier System allows you to economically and reliably distribute a coded signal to every point on the electrical power distribution system.

Transmitters

The Powerline Carrier System Transmitter connects directly to the AC power wiring, either plug-in or hard-wired, and transmits a coded signal when triggered. They are available for a variety of applications, with both hard-wire and plug-in installation, those that are manually triggered by pushbutton and those that automatically triggered by a detector. They all contain a DIP switch to set an identifying code. The hard wire units are miniaturized for concealment in the electrical outlet box, behind a detector or other appliance.

In addition to the high level - zero crossing - Digital Pulse Modulation technology, each of Cepco's transmitters contains circuitry that constantly monitors the AC powerline at the zero crossings to determine whether or not a signal, or noise, pulse is present. This allows it to automatically delay its own transmission until it detects a zero crossing with no signal or noise.

In this way it is able to evade the powerline noise and the signals from other transmitters, allowing for the simultaneous operation of multiple transmitters without interference.
 

Recievers

Cepco Powerline Carrier Receivers are available for both hard-wire and plug-in installation. The hard-wire units are miniaturized for installation in an electrical outlet box behind a light, horn, or other appliance.

These are single channel units, in that they only respond to the transmitter(s) whose DIP switch setting match their own. All other transmitters are ignored.

These units are available for a variety of applications. When activated by a remote transmitter, they can supply an audible output (buzzer), a visual output, (indicator light) or an electrical output (relay). They are "non-latching" units, which automatically reset within 5 seconds after the transmitter stops signaling.
 

Monitor and Display Panels

The monitor and display panels respond to all of the transmitters, and display their location codes (DIP switch setting).

These panels contain a buzzer, to supply an audible output, a relay, to supply an electrical output, and an indicator light or display to announce the transmitters location.

These are "latching" units. Once the transmitter’s signal is received, they latch in the alarm mode, with an audible output (buzzer), an electrical output (relay) and transmitter location display, until manually reset after the transmitter has stopped signaling.

To insure reliable operation, the monitor and display panels require multiple code word commands. This means that they do not respond unless they receive at least two consecutive code words from the same transmitter (identical code words), within a 5 second time interval. This virtually insures that there will be no false alarms due to noise or transients. 
 

Signal Boosters and Couplers

Signal boosters and couplers are provided to insure signal integrity throughout the installation.

The signal boosters are used to compensate for signal loses due to long distances and/or heavy current loads.

The 3-phase coupler is used in 3-phase installations, while the transformer coupler is used in installations with multiple power transformers.

About Cepco

Cepco Products is a developer of powerline carrier products and systems. Their products are in use by major companies and institutions across the US, Canada and Great Britain. Cepco clients include: the United States Secret Service, Princeton University and California State Hospital. Cepco is currently seeking Electrical Contractors nationwide to join their installation network. By filling out the form below you can find out more regarding the advantages of using Cepco PLC systems. PLC Info Form

• Versatile and Innovative - work for a multitude of applications.

• Time Savings - utilize existing AC lines.

• Cost Efficient - reduce materials and man hours.

• Additional Services - PLC systems may allow you to offer services to your customers that were previously not part of your standard portfolio.                       PLC Info Form
   

Article by,

Paul Belcher
Cepco Products  (818) 998-8569
http://www.cepcoproducts.com